I recently purchased a boat with a MCM470 it was overheating. I took out the thermostat and did not replace the gasket. I mistakenly took the water pump cover off looking for the stat and did not replace the gasket. The boat ran fine for a while then started to overheat again. I took the pump cover off and the secondary housing for the water pump off but could not get it off because the wheel was in the way. I have checked the outdrive water pump by removing the hose connected to the heat exchanger and cranking the engine I had good lake water flow. I also cranked the engine while the internal pump housing was off and it cranked fine also. Do I just need new gaskets and a new thermostat and new internal fluid? I did take the end off the heat exchanger and it seemed open. When I do pull the wheel with my wheel puller should I have it re timed? Should I go ahead and replace the internal water pump if I have the thing apart? By the way it is a 1979 Marquis boat. Also the boat cranks over every time on the first time, it seems to run well when its not hot.
Thanks for looking,
Bobby
Thanks for looking,
Bobby